I am an English girl. My name is Mary. I'm twelve. My dad and mom are English teachers. I have a brother. His name is Tom and he is thirteen years old. We are in China now. We are in Beijing No. 4 Junior High School. Tom is in Class 4, Grade 7 and I am in Class 9, Grade 7. I have a dog. My dog looks strong. It has a big mouth and two big black ears. We have many Chinese friends here. They are good.

一只小鸭浮在平静的湖面上。图中能正确表示小鸭和它在水中所成的倒影的是(   )

弘扬中国精神，也就时要弘扬以改革为创新为核心的中华民族精神，以爱国主义为核心的时代精神。（      ）        

影响北京城址变迁的主要自然因素是（　　）